The present invention relates to heating a geological formation for the extraction of hydrocarbons, which is a technique of well stimulation. In particular, the present invention relates to an advantageous method that can be used to heat a geological formation to extract heavy hydrocarbons.
As the world's standard crude oil reserves are depleted, and the continued demand for oil causes oil prices to rise, oil producers are attempting to process hydrocarbons from bituminous ore, oil sands, tar sands, and heavy oil deposits. These materials are often found in naturally occurring mixtures of sand or clay. Because of the extremely high viscosity of bituminous deposits, oil sands, oil shale, tar sands, and heavy oil, the drilling and refinement methods used in extracting standard crude oil are typically not available. Therefore, recovery of oil from these deposits requires heating to extract hydrocarbons from other geologic materials and to maintain hydrocarbons at temperatures at which they will flow.
Current technology heats the hydrocarbon formations through the use of steam and sometimes through the use of electric or radio frequency (RF) heating. Steam has been used to provide heat in-situ, such as through a steam assisted gravity drainage (SAGD) system. Electric heating methods generally use electrodes in the formation and the electrodes may require continuous contact with liquid water.
A list of possibly relevant patents and literature follows:
US 2007/0261844Cogliandro et al.US 2008/0073079Tranquilla et al.2,685,930Albaugh3,954,140Hendrick4,140,180Bridges et al.4,144,935Bridges et al.4,328,324Kock et al.4,373,581Toellner4,410,216Allen4,457,365Kasevich et al.4,485,869Sresty et al.4,508,168Heeren4,524,827Bridges et al.4,620,593Haagensen4,622,496Dattilo et al.4,678,034Eastlund et al.4,790,375Bridges et al.5,046,559Glandt5,082,054Kiamanesh5,236,039Edelstein et al.5,251,700Nelson et al.5,293,936Bridges5,370,477Bunin et al.5,621,844Bridges5,910,287Cassin et al.6,046,464Schetzina6,055,213Rubbo et al.6,063,338Pham et al.6,112,273Kau et al.6,229,603Coassin, et al.6,232,114Coassin, et al.6,301,088Nakada6,360,819Vinegar6,432,365Levin et al.6,603,309Forgang, et al.6,613,678Sakaguchi et al.6,614,059Tsujimura et al.6,712,136de Rouffignac et al.6,808,935Levin et al.6,923,273Terry et al.6,932,155Vinegar et al.6,967,589Peters7,046,584Sorrells et al.7,109,457Kinzer7,147,057Steele et al.7,172,038Terry et al7,322,416Burris, II et al.7,337,980Schaedel et al.US2007/0187089BridgesDevelopment of the IIT ResearchCarlson et al.Institute RF Heating Process forIn Situ Oil Shale/Tar Sand FuelExtraction - An Overview